I have a Chronodot RTC (version 2.1) and I'm trying to figure out how it's supposed to be wired up to my Arduino. I've been referring to this link: http://docs.macetech.com/doku.php/chronodotThere's an Arduino program on there, but it doesn't indicate anywhere in the program the pins on the Arduino to which I need to connect the wires. Anybody know? Thanks.

Macetech's example code uses the Wire library, and from the documentation:On most Arduino boards, SDA (data line) is on analog input pin 4, and SCL (clock line) is on analog input pin 5. On the Arduino Mega, SDA is digital pin 20 and SCL is 21

Thanks. I wired the SDA and SCL pins to A4 and A5, respectively, and I wired the VCC and GND pins to power and ground on my breadboard, respectively. I uploaded their example program and opened the serial monitor, but I'm not getting any data. Do you have any idea what the problem could be? Do I need to wire any of the other pins on the Chronodot?

You need pullup resistors on the A4/A5 lines also (like 10K) if the chronodot does not include them:

"The SDA and SCL pins are used to communicate with the ChronoDot, using the I2C standard interface. The I2C bus requires pullup resistors from SDA and SCL to VCC. Since many devices that have I2C buses already have the resistors in place, these are not provided with the ChronoDot. But there are two locations for 4.7K or 10K resistors to be soldered, in case your controlling device does not have its own pullup resistors. "

Thanks, I tried using 10K resistors. I simply connected one leed on each resistor to the VCC rail of my breadboard and the other leeds to the SDA and SCL pins. No results. Do I actually need to solder the resistors onto the Chronodot board?

No, that is not a requirement. Here is a useful I2C troubleshooting sketch. It scans all possible legal I2C addresses and tells you if there is a response from any address. After uploading, just open the serial monitor and set to 38400 baudrate, then press the reset button on the board and see if your Chronodot is answering the inquirey.

Thanks retrolefty. Here's what I got…I'm attaching a screencap to this message.

I'm also attaching a picture of what I have wired up; maybe you guys can tell me if I got anything blatantly incorrect?Also, there are two places that say R1 and R2 as you can see here in this image: http://www.adafruit.com/images/medium/ChronoDotV2_MED.jpg do I need to solder 10K resistors into those holes?

Ok, the problem is how you are mounting the chronodot to your breadboard, you are shorting all the pins together on each side of the dot, and not actually wiring anything to any of the dot pins. Breadboards holes are all wired together only on the 5 holes in a row. You need to rotate the chronodot 90 degrees and have it straddle the center section. Does that make sense? You maybe could use a ohm meter to get a better idea of how the breadboard holes are arranged and used?